Thanks to a combination of impenetrable, concrete surfaces and lack of moisture in the surrounding areas, these cities will become hot spots during a heatwave.

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A mass of air conditioning units hang off the back side of a row of buildings that open onto the fashionable Boat Quay area. In Singapore's tropical climate, air conditioning has become a must.

This is then only made worse by the overuse of air conditioners, which also pump heat out into the wider urban environment.

Despite a predicted increase in rainfall across the board, the way we build our cities almost completely cancels out any positive effects this could convey.

Now maintain that heat level through the night, and you're creating an environment where literally no-one in the city can escape the heat.

The problem is intrinsically tied to a city's need for naturally occurring moisture in the surrounding area. If it doesn't have enough moisture, it won't cool as quickly as areas that that have plentiful supplies of it.

The results of which would be severely unpleasant for an awful lot of us.

"Given that 50 percent of the world's population currently lives in cities, and that percentage is projected to increase to 70 percent by year 2050, there is a pressing need to understand how cities and landscapes are affected by heatwaves," said Lei Zhao, a postdoctoral research associate at Princeton's programme in science and technology.

One of the solutions for this is clearly changing the way that we build or expand our cities.

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The Bosco Verticale buildings in autumn in Porta Nuova complex. The complex is an 11-story office building. Its height is 111 meters and 76 meters that will gather more than 900 trees of 96,000 sq ft. terraces.

By building "green" buildings – or at least, buildings with "green" roofs – we can use natural vegetation to mitigate some of the heat that's being trapped down on the surface.

"Our findings underscore the importance of implementing heat-mitigation strategies today. They also highlight the need for more studies of this nature, to give us a better idea of the cities and landscapes that are most affected now and also under additional greenhouse warming," said co-lead author Michael Oppenheimer, professor of geosciences and international affairs at the Princeton Environmental Institute.